Introducing AMD 785G
For the last several years AMD has delivered a series of solid, cost-effective mainstream chipsets with integrated graphics. First with the original 690G which offered a wealth of features and surprisingly competent IGP performance. Then later with the 780G and 790GX chipsets, which added a little more graphics horspower and IGP features, while keeping the price palatable. Now AMD is ready to kick it up another notch with today's announcement of the new 785G chipset.
You might not be entirely surprised to hear the 785G being announced. The 785G is one of the worst kept secrets this season, with plenty of leaks and glimpses over the past month. However, today we are able to bring you full coverage of the new chipset with a complete shakedown on our test bench. We have three retail samples in our lab from ASUS and Gigabyte, and we're going to lay them out spread eagle before your ogling eyes. But first, let's check out what's new in AMD's latest mainstream chipset.
The block diagram above shows a high-level overview of the chipset's main features and illustrates how each component is connected in the architecture. The first thing you'll notice is the big Athlon II badge at the top. While the 785G is compatible with all existing AM3 processors, AMD seems to think the Athlon II is an ideal companion for 785G, considering its affordable price point.
Another obvious new addition to the 700 series is DDR3 support. While the 780G and 790GX were primarily DDR2 chipsets, the 785G swings both ways. The 785G northbridge can also come partnered with either the SB710 or SB750 southbridges. While both the SB710 and SB750 southbridges offer native support for RAID 0, 1 and 10, the SB750 gets the addition of RAID 5 support. Perhaps the biggest new feature offered by the 785G over its predecessors is a Radeon HD 4000 series integrated graphics processor.
The 780G had been equipped with a Radeon HD 3200 which was clocked at 500MHz, while the 790GX had a HD 3300, which was essentially just a HD 3200 with a higher 700MHz core clock. The new 785G is equipped with a Radeon HD 4200 which is clocked at 500MHz.While the HD 4200 carries the same default clock as the older Radeon HD 3200 IGP, it offers a host of new features which help boost performance. And as we'll see in later pages, there also seems to be quite a bit of room left for overclocking.
Like all Radeon 4000 series cores, the HD 4200 supports DirectX 10.1. It also offers HDMI 1.3 compatibility and it has AMD's second generation Universal Video Decoder (UVD) technology which allows the GPU to assist in decoding video during playback. New in UVD2 is support for multiple stream acceleration (useful for Picture-in-Picture) and a host of video quality enhancement features like Dynamic Contrast, HD Flesh Tone Enhancement and HD Color Vibrance.
Like all recent AMD IGP equipped chipsets, the 785G offers support for Hybrid CrossFire, which allows you to link the IGP up with a discrete graphics card for additional performance. Partnering the IGP with a discrete Radeon card (up to the HD 3450) can boost performance, though higher performance Radeons will likely perform best on their own. Lastly, as we draw nearer to Windows 7's public release, the new 785G comes with a full set of Windows 7 WHQL drivers.
According to AMD, today on the day of launch, there will be about 30 retail ready 785G based boards available from 9 manufacturers. We have three of these in our lab, the M4A785TD-V EVO from ASUS, as well as Gigabyte's GA-MA785GMT-UD2H and GA-MA785G-UD3H. Let's take a look at what they have to offer and then we'll put 785G through some benchmarks to see how it stacks up to the competition.